Long chain branching in ethylene-based interpolymers, for example, EPDM interpolymers, is typically controlled by either reactor conditions and/or the use of branching agents. In some EPDM polymerizations, branching agents, such as vinylnorbornene or 1,5-hexadiene, are used to produce H branches, but these compounds are prone to form gels in the final interpolymer. Increasing ethylene conversion or polymer content typically increases the amount of long chain branching in the final polymer; however, any increase in the ethylene conversion can lead to undesired decreases in catalyst efficiency, and further the polymer content is limited by solution viscosity. There is a need to modify and control long chain branching levels in an ethylene-based interpolymer, without using reactor conditions that limit catalyst efficiency, and without using branching agents that are prone to increase gel levels in the final polymer. This need has been met by the following invention.